Stop Leaf Septoria (Yellow Leaf Spot) in Its Tracks! Sometimes called “yellow leaf spot” or “leaf septoria,” this condition is caused by a fungus (or sometimes a bacteria) that attacks cannabis plants and usually appears in warm, wet weather. The symptoms first appear on the bottom leaves of the plant. The spots may have darkened borders and may have a hard growth in the middle like a little pimple, but the thing that makes the spots the most unique is they are often very uniform, like little circles. Each spot is the receptacle of a spore (ewwww) which look like tiny dark specks in the center of each spot. Although the spots often appear yellow like in the picture below, they will start turning brown over time. So if you see round brown spots on your cannabis leaves it could also be caused by leaf septoria. This fungus spores may stay in the soil over the winter, and attack your plants in the summer. Immediately (and carefully) remove all affected leaves to get rid of as many spores as possible. Prune any leafy parts of the plant to improve circulation through the plant Avoid getting water on the leaves or laying on top of each other – you want to avoid moisture Make sure to keep the ground under your plant clean. Adding mulch can also help prevent spores from spreading. Keep plants healthy, sicks plants are much more susceptible to leaf septoria than healthy plants One way to help prevent this fungus from attacking your plants is to rotate crop sites or move to a new location every year. A copper based fungicide or a broad spectrum fungicide may be effective at stopping the fungus from spreading though they are best used as a preventative. Depending on exactly what’s causing your leaf spot, Neem Oil may be used to help combat the problem. Neem Oil will leave an unpleasant taste/smell on buds when used to treat flowering plants, so don’t let this stuff get near your buds! You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly, since neem oil and water can separate easily. Try spraying just a small part of the plant and see how it reacts first before spraying the whole thing. Leaf Septoria (Yellow Leaf Spot) On Cannabis Plants. Cannabis plants, unfortunately, are susceptible to a wide variety of diseases and pests. Leaf septoria is one such disease, and can greatly damage the foliage, development, and yield of your cannabis plant. Learn how to properly treat and prevent leaf septoria from devastating your crop. Leaf septoria is a harsh plant disease that regularly affects the foliage of a variety of plants, including cannabis.
If not handled properly, leaf septoria can be devastating to plants, destroying foliage, stunting their growth, and ultimately affecting the size and quality of their yields. In this article we take a close look at cannabis leaf septoria, what it is, and how to treat/prevent this disease from affecting your cannabis crops. Leaf septoria, also known as septoria leaf spot or yellow leaf spot, is a plant disease caused by a specific kind of fungus known as Septoria lycopersici. This fungus usually overwinters on dead foliage or common garden weeds. Fungus spores can also spread onto equipment like garden stakes and netting, before germinating when conditions are right. Leaf septoria can be an extremely damaging disease, greatly affecting the foliage and growth of a variety of plants, including tomatoes, parsley, and obviously cannabis. As the name suggests, leaf septoria is characterized by yellow and brown spots forming on both the upper and lower sides of leaves. The spots tend to be circular with dark brown margins and tan or greyish centers. Leaf septoria usually affects plants just after they enter the flowering stage and usually forms on lower leaves first.
As the disease develops it spreads its way upwards, quickly affecting multiple leaves all across the plant. Affected leaves will usually turn slightly yellow, then brown, and eventually wither completely.